The aftermarket is no longer the only way to modify or customize your car. Auto manufacturers have noticed the enormous amount of money spent beyond their dealership doors and are quickly forming tuning and customization divisions of their own. And the manufacturers offer something many aftermarket companies can't: a factory warranty. And with a lot more R&D money at their disposal, a manufacturer-tuned car usually performs better than stock, which isn't always the case with tuners.

The most notable example of manufacturer customization is Porsche, which has been offering customer-specific cars for decades through its Porsche Exclusive Center in Zuffenhausen, Germany. You can custom-tailor your new Porsche just about any way you'd like — special paint, wheels, body pieces, custom gauges — for a price, of course.

Here are a few others: Minis can be tailored with a multitude of mirror and roof colors, as well as special country flags for the roof and the John Cooper Works package. Honda offers go-faster goodies through its HFP division (Honda Factory Performance), while Acura does the same with A-Spec. Audi offers an S-Line of performance/body accessories, Nissan has its Nismo-brand hop-ups, and Scion offers dealer-installed "aftermarket" options on everything from wheels to gearshift knobs to superchargers through TRD (Toyota Racing Development, Toyota's in-house tuner).

Even the American manufacturers are getting onboard — Chevrolet has its SS line, Ford has SVT and Chrysler, Dodge and Jeep have SRT (Street and Racing Technology), which is their own "speed shop."

Of course, Maybach is the most extreme of them all, with every car completely custom ordered by each prospective owner. — Mike Monticello